Method of regrinding reamers.



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NETE@ TATES FATENFI OFFICE.

JOHN C. GLENZER, OF HIGIIJJAND PARK, MICHIGAN, ASSIGNOR TO DETROIT REAMER SALVAGE COMPANY, OF DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN.

METHOD OF REGRINDING- REAMERS'.

Application filed February 17, 1916.

To all whom t may concern.'

Be it known that I, JOHN C.' GLENZER, a citizen of the United States of America, re siding at Highland Park, in the county of Vayne and State of Michigan, have invented Certain new and useful Improvements in Methods of Regrinding Beamers, of which the following is a speciiication, reference being had therein to the accompanying drawings.

The invention relates to the process for restoring or re-grinding reamers which have become worn by use and has more particular reference to the method of re-centering the reamers preparatory to the grinding operation.

In the original construction of reamers it is usual to provide the same with centers for mounting in relation to the tool by which they are fashioned. In subsequent use, however, these centers are frequently ground away or mutilated so that they cannot be used in the restoring operation. As the metal is hard it is difficult or impossible to re-center the reamer by the usual centering tools. I have therefore overcome the difliculty by proceeding as hereinafter described and shown in the drawings, in which,-

Figure 1 is a perspective view of a reamer before the re-centering operation; Fig. 2 is a similar view showing the first operation;

Fig. 3 is a central longitudinal section showing the second operation; Fig. 4 is a similar view showing the nal operation; Fig. 5 is a perspective View of the restored reamer; and Fig. 6 is an elevation of the re-centered tool engaged with supporting centers.

A is a reamer, which as shown in Fig. 1

Speci'cation of Letters Patent.

Serial No. 78,828.

has been ground off at the end so as to destroy or mutilate the center B on which it was originally fashioned. Inasmuch as the metal is hardened and it is undesirable to draw the temper it would be practically impossible to form a new center in the tool by the methods originally employed. It would also be a diiiicult operation to grind or cut a center by any instrument of sufficient hardness to operate upon the tool. The metal is, however, readily cut by an emery or other abrasive wheel, and I therefore first employ such a wheel for cutting away the material at the center, preferably forming a groove or channel C diametrically across the tool as shown in Fig. 2. In the channel thus formed I then place an insert D formed of softer metal, this being so fashioned that it may be pressed or driven into a retaining engagement. The center is then cut in the soft metal insert by any suitable means such as the usual center-cutting tool E, after which the reamer may be mounted upon supporting centers and the tool employed for re-fashioning.

What I claim as my invention is In the methodof restoring hardened tools, the re-centering of the hardened tools by grinding a recess or channel in the end portion of the tool securing a soft metal insert in said recess or channel and cutting a center in the insert.

In testimony whereof I aflix my signature in presence of two witnesses.

JOI-IN C. GLENZER.

Witnesses:

WM. J. BELKNAP, PHYLLIS CoBUnN.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents,

Washington, D. C.

Patented Feb. 6, 1917. 

